Where do I enter my spouse's 1099-SM? It's not in the list.

If you are filing the 2024 tax return as Married Filing Jointly, both your name and your spouse's name will be on the entry screen for the Form SSA-1099

To enter Social Security benefits reported on form SSA-1099

Click on Federal Taxes (Personal using Home and Business)
Click on Wages and Income (Personal Income using Home and Business)
Click on I'll choose what I work on (if shown)
Scroll down to Retirement Plans and Social Security
On Social Security (SSA-1099, RRB-1099), click the start or update button

Or enter ssa-1099 in the Search box located in the upper right of the program screen. Click on Jump to ssa-1099

Do you mean a SSA1099?  For Social Security?

 Go to Federal> Wages & Income>>Retirement Plans and Social Security  (SSA1099 and 1099RRB) to enter your SSA1099.